Heisenberg’s Uncertainty Relation: Violation and Reformulation

The uncertainty relation formulated by Heisenberg in 1927 describes a trade-off between the error of a measurement to know the value of one observable and the disturbance caused on another complementary observable so that their product should be no less than a limit set by Planck’s constant. In 1980, Braginsky, Vorontsov, and Thorne claimed that this relation leads to a sensitivity limit for gravitational wave detectors. However, the present speaker in 1988 constructed a model of position measurement that breaks both this limit and Heisenberg’s relation. In this talk, we discuss the problems as to how we reformulate Heisenberg’s relation to be universally valid and how we experimentally quantify the error and the disturbance to refute the old relation and to confirm the new relation.